About 6 million people in the developed countries of the world are confined to wheelchairs due to lower limb disabilities. Such lower limb disabilities may be caused by injury such as spinal cord injury or traumatic brain injury, or by such diseases as stroke, cerebral palsy, spinal bifida, multiple sclerosis, or by other types of injuries or diseases. Confinement to a wheelchair may cause severe physiological and psychological deterioration, and may lead to poor health or quality of life, or low self-esteem. As a result, confinement to a wheelchair may lead to high medical expenses. Wheelchair users strive for assistive devices that would enable upright mobility, and thus improve their health, quality of life, and position in society.
Exoskeleton devices that attach to the body of a disabled person and enable the person to walk have been described. Such an exoskeleton device may be controlled to perform a variety of movements. Such an exoskeleton device may be operated to enable the person to walk without the assistance of others, and while standing or while leaning on crutches. Exoskeleton devices may be controlled to enable activities and access to places that may be difficult or impossible using a wheelchair.